哮喘小鼠气道IL-6、信号转导和转录激活因子3的表达与活化及其与气道炎症的关系

摘要

目的 研究气道IL-6、信号转导和转录激活因子3(STAT3)在哮喘小鼠气道中的表达与活化,及其与气道炎症的关系.方法 30只Balb/c小鼠随机分为正常对照组、哮喘未干预组和AG490干预组,每组10只.建立小鼠哮喘模型,苏木精-伊红(HE)染色观察肺组织病理改变,收集支气管肺泡灌洗液(BALF),进行炎性细胞分类计数,EUSA检测BALF中IL-4、IL-5、IL-6水平,免疫组织化学染色检测各组肺组织中STAT3表达,蛋白免疫印迹法检测肺组织STAT3和p-STAT3水平.应用SPSS13.0软件进行统计学分析.结果 HE染色显示哮喘未干预组可见明显气道炎症改变,AG490干预组炎症改变较轻;AG490干预组BALF中细胞总数、嗜酸粒细胞(EOS)以及IL-4、IL-5水平均低于哮喘未干预组(P<0.05).哮喘未干预组气道STAT3表达水平、肺组织STAT3和p-STAT3水平明显高于对照组(P<0.05),AG490干预组肺组织p-STAT3水平明显低于哮喘未干预组(P<0.05).哮喘小鼠气道STAT3表达水平及肺组织P-STAT3水平分别与BALF中EOS计数、IL-4、IL-5、IL-6水平等呈正相关(P<0.05).结论 哮喘小鼠气道STAT3蛋白表达上调及活化程度增加,与气道IL-6的升高和Th2优势的气道炎症相关,IL-6/STAT3信号通路可能参与哮喘气道炎症的形成.%Objective To study the expression and activation of IL-6, signal transducers and activators of transcription 3 ( STAT3 ) in airway of asthmatic mouse model and its association with airway inflammation.Methods Thirty Balb/c mice were randomly divided into control group ( n = 10 ), asthma group ( n = 10 ) and AG490 group ( n = 10 ).The mice were sensitized with ovalbumin to establish the asthmatic model.The histological changes were evaluated by hematoxylin and eosin staining, bronchoalveolar lavage fluid ( BALF ) were collected, the total cell and the cell differentials were counted, the levels of IL-4, IL-5 and IL-6 in BALF were measured by enzyme-linked immunosorbent assay.The expression of STAT3 in airway were detected by immunohistochemistry technique; lung tissue extracts were analyzed for total STAT3 and p-STAT3 by Western blot.SPSS13.0 software was used to analyze the data.Results Typical inflammatory changes were shown in asthma group compared with AG490 group.The total cells, EOS amounts and levels of cytokine in BALF of asthma groups were significantly higher than in those in AG490 group ( P ＜ 0.05 ).The expression of STAT3 and p-STAT3 in asthma group were significantly higher than that in control group ( P ＜ 0.05 ), The level of p-STAT3 in AG490 group were significantly lower than that in asthma group (P ＜ 0.05 ).The level of STAT3 in airway and level of p-STAT3 in lung tissue had positive correlations with IL-4, IL-5 and IL-6 in BALF ( P ＜ 0.05 ).Conclusions The expression and activation of STAT3 in airway were up-regulated in asthmatic mouse model, its level was associated with Th2-biased airway inflammation and increment of IL-6 in airway, IL-6/ STAT3 signaling pathway may play an important role in airway inflammation.